Let us sidetrack for a moment, and talk about "precedence" in the Bible.
What is "precedence?" George Washington provided us with a secular example of precedence in U.S. History. George Washington was the first President of the United States. He only served two terms as President—a total of eight years. George Washington set a "precedent" of serving for only two terms in office. Because of this precedent, each president since that time has limited himself to two terms. (This precedent was eventually broken by President Franklin D. Roosevelt, who served for almost four terms, and died in office. Because of Roosevelt, the 22nd amendment to the U.S. Constitution was ratified in 1951, limiting the office of the President to two terms of office—in accordance with the "precedent." So, although limiting any president to two terms in office is now a matter of Constitutional law, the "precedent" set by George Washington was followed nonetheless for about 160 years, and was then used as the pattern in which the amendment was written!) This is an example of a precedent.
Question: Was Moses circumcised before the passover? How about the patriarch Jacob, or the prophet Samuel? The Bible doesn't say, so how can we know?
A Biblical example of precedence can be found in circumcision. God said to Abraham:
GENESIS 17:9 ¶ And God said unto Abraham, Thou shalt keep my covenant therefore, thou, and thy seed after thee in their generations.
GENESIS 17:10 This is my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised.
GENESIS 17:11 And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you.
GENESIS 17:12 And he that is eight days old shall be circumcised among you, every man child in your generations, he that is born in the house, or bought with money of any stranger, which is not of thy seed.
GENESIS 17:13 He that is born in thy house, and he that is bought with thy money, must needs be circumcised: and my covenant shall be in your flesh for an everlasting covenant.
GENESIS 17:14 And the uncircumcised man child whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people; he hath broken my covenant.
Was Moses circumcised, before the passover? He was. Was Samuel circumcised? Yes, he was. The Bible does not specifically say that each–and–every–one–of–these–men were, so how can we tell? For the purposes of our reading the scriptures, the precedent of circumcision was established with Abraham, and it is understood that Moses, Jacob, Samuel, and the like, were circumcised because of this precedent.
This must be a matter of precedence, for Jesus did mention:
JOHN 7:22 Moses therefore gave unto you circumcision;
(not because it is of Moses, but of the
fathers;) and ye on the sabbath day circumcise a
man.
This was said because Moses wrote Genesis after the fact.
(Moses himself was not born until the beginning of the book of
Exodus, which comes after Genesis).
Just as how the Bible never actually says that Moses or Jacob, Samuel, or any of the Judges, or David or Solomon were actually circumcised (though we "know" good–and–well that they were), so too is baptism in the name of Jesus Christ a precedent in the New Testament as well. In the book of Acts, whenever someone becomes "saved," it does not specifically say each–and–every–single–time that that man was baptized.
Likewise, the book of Acts does not state each time that the saved person believes either, though through precedent and overall context, we "know" that they did believe.
For example, in Acts 18:24-26, it says that Apollos "was taught the way of God more perfectly." It doesn't say that he believed it. Likewise, in Acts 19:1-6, it never states plainly that those disciples believed on Christ Jesus as John said to. It only says that they were baptized in His name. In either case, we "know" that these particular people actually believed in Jesus Christ, through previous "precedent."
Before Abram was circumcised, God had already counted him righteous for his faith:
GENESIS 15:6 And he believed in the LORD; and he counted it to him for righteousness.
This was at least 13 years (cf. Gen 16:16 and Gen 17:1) before God told Abraham to get circumcised (and to circumcise his house). Had Abraham not been circumcised, what would have become of him? God told Abraham:
GENESIS 17:14 And the uncircumcised man child whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people; he hath broken my covenant.
If Abraham were the typical American, he would have said that God had already declared him righteous, and would not have been circumcised. Fortunately, Abraham is not a typical American, and I'm grateful for that! Abraham obeyed, because he believed. Abraham taught his descendants to obey this too (cf. Genesis 18:17-19), lest they be cut–off for breaking the covenant.
Therefore, in light of the following:
ACTS 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
...in light of all of these things, it is only reasonable to assume, when we read from the New Testament, that baptism, water baptism, in the name of Jesus Christ, as stated in Acts 2:38 is a precedent.
Again, baptism is being mentioned as a precedent, because in the book of Acts, the Bible does not say at–each–and–every–single–incident of someone becoming saved that they were baptized. With baptism as a precedent, we can be sure that they were (just as circumcision was a precedent in the Old Testament, so we know that Moses, Sampson, Samuel, David and Solomon were circumcised, even though nothing specifically states that they were).
Certainly, it is understood that whenever somebody was saved, that he likewise believed, even though it is not mentioned in each instance. Without the death and resurrection of Jesus Christ, salvation would not be possible for us. Without faith, it is impossible to please God (Hebrews 11:6), therefore everything that is done must be done in faith, including baptism (Mark 16:16). Faith too is a precedent, for The Book of Acts does not always say that saved people "believed" (cf. Acts 2:38; Saul in Acts 9, Acts 19:1-6, etc.), though through precedent, we know that they did.